Signal provision for locks



Augzz, 1950 J.- L SMITH ETAL SIGNAL PROVISION FOR LOCKS Filed Nov. 28, 1947 lflldkL/lT/IV JoH/v LSM/TH DALE L. HARDING INVENTORS Patented Aug. 22, 1950 UNITED STATES m NT oFFicE SIGNAL PRDVISION FOR LGCKS John L. Smith and Dale L. Harding, Decatur, Ill. 7 Application November 28, 1947, Serial No. 788,334- 3 Claims. (o1. zoo-44) This invention relates to a signal provision for looks to indicate that the key is not removed after using the lock. It has more particularly to do with the ignition lock of an automobile and other app-lied locks, unauthorized use of which it is desired to prevent.

An object is tov provide generally upon signal provisions of such character and more specifically for locks of the tumbler-cylinder type.

Another object is to provide a signal means which is provided for direct control and operation by a lock tumbler as actuated upon insertion, turning and removal of the key in and from the lock and Without appreciable alteration in the lock used.

Othe objects and advantages to be attained will hereinafter more fully appear in the following description.

In the drawings, illustrating a practical but non-limiting exemplification of the invention,

Figure 1 is a longitudinal section, taken on the line l-l of Figure 2, of a lock and an associated switch it is to control and actuate, the key being inserted in the lock;

Figure 2 is a cross section on the line 22 of Figure 1;

Figure 3 is a view similar to Figure l, but with the key removed;

Figure 4 is a view similar to Figure 2, but with the key removed;

Figure 5 is a view similar to Figures 2 and 4, but with the key inserted and turned clockwise to accordingly rotate the tumbler cylinder so as to close the switch and break the signal circuit; and

Figure 6 is a diagram showing a plan of installation and Wiring of the invention for use on an automobile or the like.

Referring now to the drawing in detail (see Figures 1, 3 and 6), the numeral ill designates the housing of the lock shown as bolted to a portion I I back of a dashboard l2.

The tumbler cylinder 5 3 of the lock is fitted rotatably in the bore of a reduced cylindrical portion of the housing It which extends between the partition M and dashboard 52 (see Figures 1 and 3). This tumbler cylinder l3 has a flange Ida at its outer end abutting the dashboard I 2.

Fitted and working in diametrical throughslots M in the cylinder !3 are tumblers l5, which latter, in one retracted longitudinal position thereof, engage in a longitudinal groove in the said reduced cylindrical portion of the housing ill (see Figures 3 and 4) and thus prevent rotation of said tumbler cylinder 13, that is to say, in the normal position of the tumblers l5 and while the key is removed from the lock.

When the key 2b is inserted (see Figures 1 and 2) the tumblers 55 are moved clear of said longitudinal groove in the reduced cylindrical portion of the housing l0 and the tumbler cylin- 2 der I3 is free to be rotated in the housing by turning the key. For the rotated position of the tumbler cylinder l 3 see Figure 5.

In the particular showing in the drawings, the housing it is made of an insulative or electrically non-conductive material, but the tumbler cylinder i3 is electrically conductive. In this case an electrical-spring contact member i6 is placed externall on the reduced cylindrical portion of th housing l9 and i s free end portion is turned at a right angle and inserted freely movable in a transverse aperture E ia in said housing part and into a position to be engaged by one of the tumblers when the key it is inserted to actuate said tumbler (see Figures 1 and 2). However, by the same token, if the housing'lll is made of electrically conductive material, the contact member it must be obviously insulated from the housing. In any case, the contact member 15 has a circuit wire C attached thereto.

It is here noted that as far as the present invention is concerned, the lock itself may be of different precise details of construction, but, in any case, the invention is characterized b the actuation and control of the signal means direct- 1y by and with at least one of the lock tumblers. In this-connection, too, the form and position of the contact member it may also be changed in some adaptations of the invention.

Normally, with the key 29 removed from the lock (see Figures 3 and 4) the contact member l6 projects with ample clearance into amplespace opposite the retracted opposed tumbler l5 and free of engagement with the housing it. Thus, when the key 28 is inserted, the correlated tumbler l5 is moved into contact with the contact member l6, thereby completing an electrical circuit of a signal device which may be an audible one, such as a bell, buzzer or the like, or else a visible one, such as a lamp or an illuminable sign or the like. In the showing, the complete circuit is through the wire C, contact mem ber i6, tumbler l5, cylinder 3, a switch element l8?) to be presently described in more detail, a wire D, battery B which may be the regular storage battery on the car or special one, as may be desired, and a signal device A, which may obviously be audible or visible, back to the wire C. This circuit is illustrated in diagram in Fig. 6.

It is to be understood that when the lock is in normal position, with the key 20 removed, the signal circuit is broken and the signal A will not sound or be seen, as the case may be, but, when the key 26 is inserted, the signal will sound or be observed, and until the tumbler cylinder I3 is rotated to close the ignition switch or for some other useful effect for which the lock is provided.

Obviously, some suitable and approved provision must be made so that the contact member I6 is not in electrically conductive contact with the tumbler cylinder I3 when the latter is rotated as indicated in Figure 5 to move the tumbler I5 out of electrically conductive engagement with said contact member I6. This is accomplished by either cutting away or grooving the adjacent peripheral portion of the cylinder I3 and leaving the same open so as not to be engaged by the member I6, or otherwise by filling in this cutaway or grooved portion of the cylinder with a suitable insulation material.

In this connection, it is noted that, in the showing, a restricted open channel or space is provided alongside of the diametrical opening in the cylinder I3 where the tumbler I5 is located and operates. This is for the reception of a spring 2i which is held in place by a longitudinal wire 22 fastened in place on the cylinder. The spring 2! exerts a constant force upon a lug I5a on the adjacent side of the tumbler I5, to normally maintain the tumbler in a downwardly retracted position until it is raised by the. insertion of the key 2|]v in the lock. Therefore, the provision of this spring-accommodating channel or space affords at its top ample clearance to prevent engagement of the contact member I6 with the tumbler cylinder I3 in its rotated position as caused by the turning of key 20. as shown in Fi ure 5..

Obviously the several tumblers I5 have rectangular openings 23 therethrough for the passage of the key 20 and for permitting operation of the tumblers.

The ignition switch to which the lock is applied in use may be of any conventional or desired type. That shown is of a well-known standard make. Suffice it to say that the tumbler cylinder I3, as shown. has a. boss I! at its inner end engaging the head portion l8a of the switch device I8b which is thus caused to rotate on its base I8 when the key 20 is turned by the hand of the operator.

The details of the switch are not shown in the drawings as the same, per se, are not a, part of the present invention. So, too. the ignition system is not shown in the drawings for the same reason. In the drawings (see Figures 1, 3 and 6) only one wire E of the ignition system and another wire F which leads to a, panel gage or the like on the dashboard, is shown.

From the foregoing it is apparent that a practical and efiicient signal provision is produced to indicate that a key is inserted in a lock and to indicate that the same is not removed after use. This is especially applicable and desirable in connection with an ignitionsystem of an. automobile to prevent such oversight as that of leaving the key in the lock of a parked automobile and the possible theft of same or other unauthorized use thereof. It is also useful for looks in general to warn one that the key is left. in the look, after the latter hasv been actuated to a position whereby the key may be withdrawn.

While the illustrated provision and arrangement is a practical exemplification of the invention, the same is not a limitation, as modification and change is contemplated within the spirit and scope of the appended claims.

What is claimed is:

1. In a lock having a housing and a rotatable tumbler cylinder in the housing, an electrical contact member on the housing in opposed relation to the tumbler cylinder as a part of a normally open electrical signal circuit, at least one tumbler of the cylinder, in addition to normally holdin the cylinder from rotation in the housing, engaging electrically with said contact member so as to close said signal circuit upon insertion of a key into said cylinder in the normal position of the same and the said engagement continuing until the key is withdrawn while the cylinder is in such position.

2. A lock provision as set forth in claim 1, wherein the cylinder-holding effect of the tumbler is broken and a turning of the key still inserted and the consequent rotation of the cylinder moves the tumbler out of engagement with the contact member, thereby breaking the signal circuit until said cylinder is. rotated back to normal position by said key.

3. In association with an electric signal of an electric circuit, a lock having tumblers which respond to key action, one of said tumblers bein in correlation to a contact. member of said electric circuit for the signal but normally out of engagement with said contact member, a key insertable in the lock in the normal condition of the same and when inserted being effective in releasing the tumblers from holding effect and moving the contact-engagin tumbler into engagement with said contact member, and a turning of the inserted key causes a disengagement of the tumbler from the contact member.

JOHN L. SMITH. DALE L. HARDING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,330,206 McQuarrie Feb. 10, 1920 2,215,162 Scott Sept. 17, 1940 

